Which sentence uses an intransitive verb?

a. they will take their project to the science fair.

b. sean took notes about the slides.

c. jan used her new microscope.

d. jan and sean worked hard on their project.

The correct answer for this question is "d. jan and sean worked hard on their project." The sentence that uses an intransitive verb is this 'jan and sean worked hard on their project' because from the definition of an intransitive verb, the verb modifies directly to the indirect object. From the sentence, the direct object is hard and the indirect object is project.